(-) -Epipodophyllotoxin (2) is an antiproliferative agent against cancer cells isolated from American mayapple Podophyllum peltatum, with GI50s of 0.36 and 0.24 μM in HeLa cells and MCF-7 cells, respectively. (-) -Epipodophyllotoxin can inhibit mitotic spindle assembly in vitro[1].